Check handle to close in current loop when loop_gc

* Fix luvit#437
* Fix luvit#599

src/luv.c

@@ -794,8 +794,8 @@ LUALIB_API void luv_set_cthread(lua_State* L, luv_CFcpcall cpcall) {
 
 static void walk_cb(uv_handle_t *handle, void *arg)
 {
-  (void)arg;
-  if (!uv_is_closing(handle)) {
+  uv_loop_t* loop = arg;
+  if (handle->loop ==loop && !uv_is_closing(handle)) {
     uv_close(handle, luv_close_cb);
   }
 }
@@ -806,7 +806,7 @@ static int loop_gc(lua_State *L) {
   if (loop==NULL)
     return 0;
   // Call uv_close on every active handle
-  uv_walk(loop, walk_cb, NULL);
+  uv_walk(loop, walk_cb, loop);
   // Run the event loop until all handles are successfully closed
   while (uv_loop_close(loop)) {
     uv_run(loop, UV_RUN_DEFAULT);

tests/manual-test-exit.lua

@@ -0,0 +1,22 @@
+--come from https://github.com/luvit/luv/issues/599
+
+-- run `lua manual-test-exit.lua || echo $?`
+-- it shoud print `5`
+
+local uv = require('luv')
+
+local function setTimeout(callback, ms)
+    local timer = uv.new_timer()
+    timer:start(ms, 0, function()
+        timer:stop()
+        timer:close()
+        callback()
+    end)
+    return timer
+end
+
+setTimeout(function()
+    os.exit(5, true)
+end, 1000)
+
+uv.run()

tests/manual-test-without-uv.run.lua

@@ -0,0 +1,4 @@
+local uv = require('luv')
+
+local test = uv.new_pipe(false)
+uv.close(test)

tests/test-loop.lua

@@ -10,4 +10,28 @@ return require('lib/tap')(function (test)
     end))
   end)
 
+  test("issue #437, crash without uv.run", function (print, p, expect, uv)
+    local handle
+    handle = uv.spawn(arg[-1], {
+      args = { "tests/manual-test-without-uv.run.lua" }
+    },
+    expect(function(status, signal)
+      assert(status==0)
+      assert(signal==0)
+      handle:close()
+    end))
+  end)
+
+  test("issue #599, crash during calling os.exit", function (print, p, expect, uv)
+    local handle
+    handle = uv.spawn(arg[-1], {
+      args = { "tests/manual-test-exit.lua" }
+    },
+    expect(function(status, signal)
+      assert(status==5)
+      assert(signal==0)
+      handle:close()
+    end))
+  end)
+
 end)